Haplotypes generated for linked genetic markers, particularly markers with differing mutation rates, provide a potentially rich source of information regarding the details of human history. The first major goal of this Subproject is to develop between 25 and 50 new haplotyping systems, each consisting of a single short tandem repeat (STR), or microsatellite, polymorphism linked to one or more single nucleotide polymorphisms (SNPs). The second major goal is to determine haplotypes for these systems for approximately 1000 individuals from a geographically and linguistically diverse set of human populations. From these 50,000-100,000 haplotypes (two per individual per system) we will summarize patterns of variation in terms of genetic diversity, population heterogeneity, and linkage disequilibrium. We will then infer the extent to which population size changes (bottlenecks, expansions, contractions), population admixture, and isolation among populations have played roles in human evolutionary history. Through the development of new haplotyping systems and the inference of additional details of human history, this project will provide valuable resources and information to researchers in both medicine and anthropology.